All living cells maintain ionic gradients across their plasma membrane, and the movement of ions down these concentration gradients, through ion channels in the membrane, is of fundamental importance for many cellular functions. The central role of ion channels has of course been recognized for many years in the case of excitable cells such as neurons and muscle cells, but only recently has the development of powerful new techniques allowed an appreciation of the significance of ion channels in the functioning of many other cell types. The continued refinement of macroscopic physiological approaches, the emergence of single channel recording techniques, the increasing sophistication of biochemical purification methods, the feasibility of studying purified channel functions in artificial membranes, and the dramatic advances in molecular genetic manipulation, have contributed to our ability to study ion channels as molecular entities rather than simply as membrane processes. This proposal requests funds for a Gordon Conference that will address the most recent developments in this rapidly changing field.